1. Field
This invention relate to a cathode active material, a method of preparing the cathode active material, a cathode and a lithium secondary battery including the same
2. Description of the Related Technology
With the trend toward compact and high-performance devices, manufacturing of lithium batteries that are small, lightweight and have high energy densities have become important. The stability of lithium batteries at high capacities, high temperatures, and high voltages is an important concern especially for applications in electric vehicles.
A variety of cathode active materials has been considered to produce a lithium battery for those applications.
The Nickel-based lithium transition metal oxides materials, which include nickel (Ni), cobalt (Co), and manganese (Mn), can provide high discharge capacity per unit weight, as compared with LiCoO2. However, the nickel-based lithium transition metal oxides materials have a low mixture density and low capacity per unit volume. Thus, the nickel-based lithium transition metal oxides used in cathodehave low discharge capacity in a lithium secondary battery. In addition, when the lithium secondary battery is manufactured and operated at a high voltage using the nickel-based lithium transition metal oxides materials, stability of the lithium secondary battery may also be problematic.
Therefore, to provide a lithium secondary battery of high capacity, a method that can increase the mixture density and thermal stability of the nickel-based lithium transition metal oxides and increase the mixture density of a cathode is needed. In addition, a method that can increase the lifespan and battery stability when used at high voltage is necessary.